Can someone explain circle magic cheese (use small words please)

[Reprimand]

So I recently got the magic of faerun book and noticed Hathran is kind of the good opposite of the red wizard.

Can someone explain how Hathran is a good class and how to cheese circle magic in the most basic terms possible assume that leadership epic casting and every source is allowed.

[Extra Anchovies]

The Red Wizard entry in the DMG explains how Circle Magic works. I don't think it's OGL so I can't share the full text here, but you get some friends together and they expend spell slots to increase your CL and/or give you free Empower/Maximize/Heighten on your spells (to a maximum effective spell level of 20th). Circle Magic on its own isn't cheese; it's working as intended, but "working as intended" is still pretty crazy for something whose main function is to increase your caster level to 40.

However, Circle Magic isn't what makes Hathran so powerful. The main draw is Rashemi Spirit Magic; with an Acorn of Far Travel (http://archive.wizards.com/default.asp?x=dnd/fw/20040710a), then you're spontaneously casting from your entire spell list (or from your spellbook if you use those).

[Telonius]

Just to add on to that "caster level 40" thing ... imagine a 13th-level Cleric casting Dictum (or Blasphemy, Holy Word, or Word of Chaos). Anything nonlawful with 3HD or less is immediately killed, no save; SR applies. Now add circle magic; anything with 30 HD or less is immediately killed, no save. If the target happens to have spell resistance, it had better be SR 41 or better. Some of the direct damage spells get similarly ridiculous at much lower levels, too.

[khadgar567]

basically a plot device called stop the big bad before he kills every one in decent range( fimbulwinter combo results 150.000 km( 88 miles) of heavy winter for nearly 3 years) calculate remaining cheese your self